This application is based on EP Patent Application No. 98110803.8 filed on Jun. 12, 1998 and claims priority thereto under 35 U.S.C. xc2xa7119(a)-(d) or 35 U.S.C. xc2xa7365(a)-(b).
This invention relates to di- or triaza-spiro [4,5] decane derivatives particularly wherein R1 is C6-10cycloalkyl which may be substituted or unsubstituted or wherein R1 is decahydro-naphthalen-2-yl and compositions thereof.
OFQ, a heptadeca peptide, has been isolated from rat brain and is a natural ligand to a G-protein coupled receptor (OFQ-R), found at high levels in brain tissue. OFQ exhibits agonistic activity at the OFQ-R both in vitro and in vivo.
Julius (Nature 377, 476, [1995]) discusses the discovery of OFQ noting that this peptide shares greatest sequence homology with dynorphin A, an established endogenous ligand for opioid receptors. OFQ inhibits adenylate cyclase in CHO(LC 132+) cells in culture and induces hyperalgesia when administered intra-cerebroventricularly to mice. The pattern of results indicate that this heptadecapeptide is an endogenous agonist of the LC 132 receptor and it appears to have pro-nociceptive properties. It has been described that when injected intra-cerebroventricularly in mice, OFQ slowes down locomotive activity and induces hyperalgesia and it has been concluded that OFQ may act as a brain neurotransmitter to modulate nociceptive and locomotive behavior.
It has been found that the compounds of the present invention interact with the orphanin FQ (OFQ) receptor and consequently are useful in the treatment of a variety of psychiatric, neurological and physiological disorders.
In the following references some of these indications have been described:
Nociceptin/orphanin FQ and the opioid receptor-like ORL1 receptor, Eur. J. Pharmacol., 340: 1-15, 1997;
The orphan opioid receptor and its endofenous ligand ociceptin/orphanin FQ, Trends Pharmacol. Sci., 18:293-300, 1997;
Orphanin FQ is a functional anti-opioid peptide, Neuroscience, 75:333-337, 1996;
Orphanin FQ/nociceptin-lack of antinociceptive, hyperalgesic or allodynic effects in acute thermal or mechanical tests, following intracerebroventricular or intrathecal administration to mice or rats, Eur. J. pain, 2: 267-280, 1998;
Orphanin FQ acts as an anxiolytic to attenuate behavioral responses to stress, Proc. Natl. Acad. Sci., USA, 94: 14854-14858, 1997;
Orphanin FQ, an agonist of orphan opioid receptor ORL1, stimulates feeding in rats, Neuroreport, 8: 369-371, 1996;
Facilitation of long-term potentiation and memory in mice lacking nociceptin receptors, Nature, 394: 577-581, 1998;
Distribution of nociceptin/orphanin FQ receptor transcript in human central nervous system and immune cells, J. Neuroimmuno, 81: 184-192, 1998;
Orphanin FQ plays a role in sepsis, Prog. Clin. Biol. Res. (1998), 397, 315-325.
Objects of the present invention are the compounds of formula I and pharmaceutically acceptable addition salts thereof, racemic mixtures and their corresponding enantiomers, the preparation of the above-mentioned compounds, medicaments containing them and their manufacture as well as the use of the above-mentioned compounds in the control or prevention of illnesses, especially of illnesses and disorders of the kind referred above, or in the manufacture of corresponding medicaments.
The present invention relates to compounds of the general formula 
wherein
R1 is C6-10-cycloalkyl, optionally substituted by lower alkyl or xe2x80x94C(O)O-lower alkyl; decahydro-naphthalen-1-yl; decahydro-naphthalen-2-yl; indan-1-yl or indan-2-yl, optionally substituted by lower alkyl; decahydro-azulen-2-yl; bicyclo[6.2.0]dec-9-yl; acenaphthen-1-yl; 2,3-dihydro-1H-phenalen-1-yl; 2,3,3a,4,5,6-hexahydro-1H-phenalen-1-yl or octahydro-inden-2-yl;
R2 is hydrogen; lower alkyl; xe2x95x90O or phenyl, optionally substituted by lower alkyl, halogen or alkoxy;

xe2x80x83is cyclohexyl or phenyl, optionally substituted by lower alkyl, halogen or alkoxy;
X is xe2x80x94CH(OH)xe2x80x94; xe2x80x94C(O)xe2x80x94; xe2x80x94CHR3xe2x80x94; xe2x80x94CR3xe2x95x90; xe2x80x94Oxe2x80x94; xe2x80x94Sxe2x80x94; xe2x80x94CH(COOR4)xe2x80x94 or xe2x80x94C(COOR4)xe2x95x90;
Y is xe2x80x94CH2xe2x80x94; xe2x80x94CHxe2x95x90; xe2x80x94CH(COOR4)xe2x80x94, xe2x80x94C(COOR4)xe2x95x90; or xe2x80x94C(CN)xe2x80x94;
R3 is hydrogen or lower alkoxy;
R4 is lower alkyl, cycloalkyl, phenyl, or benzyl;
and
either a or b is optionally an additional bond,
and to pharmaceutically acceptable acid addition salts thereof.
The compounds of formula I and their salts are characterized by valuable therapeutic properties. It has surprisingly been found that the compounds of the present invention are agonists of the orphanin FQ (OFQ) receptor. Consequently they are useful in the treatment of psychiatric, neurological and physiological disorders, especially, but not limited to, amelioration of symptoms of anxiety and stress disorders, depression, trauma, memory loss due to Alzheimer""s disease or other dementias, epilepsy and convulsions, acute and/or chronic pain conditions, symptoms of addictive drug withdrawal, control of water balance, Na+ excretion, arterial blood pressure disorders and metabolic disorders such as obesity.
The following definitions of the general terms used in the present description apply irrespective of whether the terms in question appear alone or in combination, such as lower alkyl and lower alkoxy.
The term xe2x80x9clower alkylxe2x80x9d denotes a straight- or branched-chain alkyl group containing from 1 to 6 carbon atoms, for example, methyl, ethyl, propyl, isopropyl, n-butyl, i-butyl, 2-butyl, t-butyl and the like. Preferred lower alkyl groups are groups with 1-4 carbon atoms.
The term xe2x80x9ccycloalkylxe2x80x9d denotes a saturated carbocyclic group containing from 5-15 carbon atoms, preferred are cyclohexyl, cyclooctyl, cyclononyl and cyclodecyl.
The term xe2x80x9chalogenxe2x80x9d denotes chlorine, iodine, fluorine and bromine.
The term xe2x80x9cpharmaceutically acceptable acid addition saltsxe2x80x9d embraces salts with inorganic and organic acids well-known in the art for pharmaceutic purposes, such as hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, citric acid, formic acid, fumaric acid, maleic acid, acetic acid, succinic acid, tartaric acid, methane-sulfonic acid, p-toluenesulfonic acid and the like.
Preferred compounds of the present invention are those of formula I, in which R1 is C6-10-cycloalkyl, optionally substituted by lower alkyl, R2 is hydrogen, X is xe2x80x94CH(OH)xe2x80x94, xe2x80x94C(O)xe2x80x94 or xe2x80x94CHOCH3 and Y is xe2x80x94CH2xe2x80x94, for example the following compounds:
(RS)-8-(cis-4-Isopropyl-cyclohexyl)-1-phenyl-1,8-diaza-spiro[4.5]decan-4-ol,
(R)-8-(cis-4-Isopropyl-cyclohexyl)-1-phenyl-1,8-diaza-spiro[4.5]decan-4-ol,
(S)-8-(cis-4-Isopropyl-cyclohexyl)-1-phenyl-1,8-diaza-spiro[4.5]decan-4-ol,
8-(cis-4-Isopropyl-cyclohexyl)-1-phenyl-1,8-diaza-spiro[4.5]decan-4-one,
(RS)-8-(cis-4-Isopropyl-cyclohexyl)-4methoxy-1-phenyl-1,8-diaza-spiro[4.5]decane,
and
(RS)-8-Cyclononyl-1-phenyl-1,8-diaza-spiro[4.5]decan-4-ol.
Further preferred are compounds of formula I, in which R1 is decahydro-naphthalen-2-yl, 2,3,3a,4,5,6-hexahydro-1H-phenalen-1-yl, 4-methyl-indan-2-yl, octahydro-inden-2-yl and decahydro-azulen-2-yl, R2 is hydrogen, X is xe2x80x94CH(OH)xe2x80x94 or xe2x80x94CHOCH3 and Y is xe2x80x94CH2xe2x80x94.
Examples of such compounds are
(RS)- and (SR)-8-[(2RS,4aSR,8aRS)-decahydro-naphthalen-2-yl]-1-phenyl-1,8-diaza-spiro[4.5]decan-4-ol,
8-(decahydro-naphthalen-2-yl)-1-phenyl-1,8-diaza-spiro[4.5]decan-4-ol,
8-(2,3,3a,4,5,6-hexahydro-1H-phenalen-1-yl)-1-phenyl-1,8-diaza-spiro[4.5]decan-4-ol,
(RS)- and (SR)-8-[(RS)-(4-methyl-indan-2-yl)]-1-phenyl-1,8-diaza-spiro[4.5]decan-4-ol,
8-(decahydro-azulen-2-yl)-1-phenyl-1,8-diaza-spiro[4.5]decan-4-ol or
8-(octahydro-inden-2-yl)-4-methoxy-1-phenyl-1,8-diaza-spiro[4.5]decane (mixture of diastereoisomers).
The present compounds of formula I and their pharmaceutically acceptable salts can be prepared by methods known in the art, for example, by the processes described below, which comprise
a) reductively aminating a compound of formula 
with a compound of formula 
wherein R1, R2, a, b, 
X and Y have the significances given above,
or
b) reducing a compound of formula 
to a compound of formula 
wherein R1, R2, b, 
and Y have the significances given above, or
c) oxidizing a compound of formula 
to a compound of formula 
wherein R1, R2, b, 
and Y have the significances given above, or
d) reducing a compound of formula I-3 to a compound of formula 
wherein R1, R2, b, 
and Y have the significances above, or
e) alkylating a compound of formula I-1 to a compound of formula I, wherein X is xe2x80x94CH(lower alkoxy)-, or
f) hydrogenating a compound of formula I, wherein 
xe2x80x83is phenyl, to a compound of formula I, wherein 
xe2x80x83is cyclohexyl, or
g) treating a compound of formula 
with an amino thiol of the formula 
to give a compound of formula 
wherein R1 and 
have the significances given above and R2 is hydrogen or phenyl, or
h) treating a compound of formula 
with a compound of formula 
to give a compound of formula 
wherein R1 and 
have the significances given above, and R2 is phenyl, optionally substituted by lower alkyl, halogen or alkoxy, and if desired converting a racemic mixture into its enantiomeric components thus obtaining optically pure compounds, and converting a compound of formula I obtained into a pharmaceutically acceptable acid addition salt.
In accordance with process variant a) the reductive amination of a keto compound of formula II with an amine of formula III is carried out by stirring with a dehydrating agent in the presence of molecular sieves (4xc3x85), in an inert solvent, such as toluene or tetrahydrofuran (THF), at reflux temperature. An alternative method is the dehydration in the presence of an acidic catalyst with removal of water, e.g. with azeotropic removal of water, or with tetraisopropyl-orthotitanate in THF.
The obtained intermediate enamine or imine is then reduced with a reducing agent, such as metal hydrides or hydrogen in the presence of a hydrogenating catalyst, preferably with sodium cyanoborohydride in a protic solvent, for example in a mixture of THF and ethanol at acidic pH.
Examples for corresponding keto compounds of formula II are the following:
cis-octahydro-2(1H)-naphthalenone, 4-(1-methylethyl)-cyclohexanone, 2-indanone, 4-ethyl-cyclohexanone, 1,3-dihydro-4-methyl-2H-inden-2-one, 4-oxo-cyclohexanecarboxilic acid ethyl ester, cyclodecanone, (3a,RS,8aRS)-decahydro-azulen-2-on, cis-octahydro-inden-2-one, cyclooctanone or cis-bicyclo[6.2.0]dec-9-one.
In accordance with process variant b) a compound of formula I-1 or I-3 is reduced to a compound of formula I-2. This process is carried out in conventional manner with a reducing agent, preferably a metal hydride, such as lithium aluminium hydride in an aprotic solvent, for example in diethylether.
In accordance with process variant c) a compound of formula I-1 is oxidized in an inert solvent, such as in acetic anhydride in DMSO at room temperature or with 4-methyl-morpholine-4-oxide in the presence of tetra-n-propylammonium-perruthenate and molecular sieves in dichloromethane at room temperature.
The reduction of a compound of formula I-3 to a compound of formula I-1-1 and/or to I-1-2 is carried out with an inert solvent, for example in the presence of an enantioselective (enantiopure) reagent or catalyst to achieve an enantiospecific formation of one enantiomer. Preferred enantioselective reagents are chiral oxazaborolidines. The reaction is carried out in the presence of borane-dimethylsulfide in THF at about room temperature. The chiral oxazaborolidines are formed in situ from chiral 1-amino-2-indanols and borane-dimethylsulfide.
In accordance with process variant e) a compound of formula I-1 is alkylated. The preferred alkylating agent is dimethylsulfate. The process is carried out in conventional manner in an inert solvent with sodium hydride in dimethylformamide.
In process variant f) is described the hydrogenation of a compound of formula I, wherein 
is phenyl. The desired cyclohexyl ring is yielded in a protic solvent, such as methanol and in the presence of a hydrogenating catalyst, for example in the presence of platinum oxide. The reaction is carried out under hydrogen pressure between 1 and 50 bar.
The formation of a 1,3-thiazolidine derivative is described in process variant g). The reaction is carried out by treating a mixture of a ketone and an amino thiol with a Lewis acid, such as boron trifluoride diethyl ether complex, in a chlorinated solvent, for example in dichloromethane.
The process step h) describes the cycloaddition of an imine of formula VII with a nitrile oxide of formula IX to give a compound of formula I-6. The process is carried out by treating an imine with a slight excess of a corresponding hydroximinoyl chloride and a base, such as triethylamine, in an inert solvent, for example in THF, described in general in Heterocycles 36, 21-24, 1993.
Racemic mixtures can be converted into its enantiomeric components in conventional manner, for example by preparative HPLC.
The salt formation is effected at room temperatures in accordance with methods which are known per se and which are familiar to any person skilled in the art. Not only salts with inorganic acids, but also salts with organic acids come into consideration. Hydrochlorides, hydrobromides, sulphates, nitrates, citrates, acetates, maleates, succinates, methanesulphonates, p-toluenesulfonates and the like are examples of such salts.
The compounds of formula II, III, IV, V, VII, VIII, IX and XII which are used as starting materials are known compounds or can be prepared by methods known per se.
The following scheme 1 describes the cyclization of compounds of formulae IX and XII to yield compounds of formulae I-7 and I-1-3. Scheme 2 describes possible reaction variants to yield compounds of formulae I-5 and I-6 and scheme 3 describes the preparation of compounds of formula I, wherein X is S. 
wherein R1 and 
have the significances given above. 
wherein R1 and 
have the significances given above. 
wherein R1, R2 and 
have the significances given above.
As mentioned earlier, the compounds of formula I and their pharmaceutically usuable addition salts possess valuable pharmacodynamic properties. It has been found that the compounds of the present invention are agonists of the OFQ receptor and have effects in animal models of psychiatric, neurological and physiological disorders, such as anxiety, stress disorders, depression, trauma, memory loss due to Alzheimer""s disease or other dementias, epilepsy and convulsions, acute and/or chronic pain conditions, symptoms of addictive drug withdrawal, control of water balance, Na+ excretion, arterial blood pressure disorders and metabolic disorders such as obesity.
The compounds were tested for pharmacologic activity in accordance with the methods given hereinafter:
Methods of OFQ-R Binding Assay
Cell Culture
HEK-293 cells adapted to suspension growth (293s) were cultured in HL medium plus 2% FBS. The cells were transfected with the rat OFQ receptor cDNA (LC132), FEBS Lett. 347, 284-288, 1994, cloned in the expression vector pCEP4 (Invitrogen, San Diego, Calif., USA) using lipofectin (Life Technologies, Bethesda, Md., USA). Transfected cells were selected in the presence of hygromycin (1000 U/ml) (Calbiochem, San Diego, Calif., USA). A pool of resistant cells was tested for OFQ-R expression by binding of [3H]-OFQ (Amersham PLC, Buckinghamshire, England). These cells (293s-OFQ-R) were expanded for large scale culture and membrane preparation.
Membrane preparation
293s-OFQ-R cells were harvested by centrifugation, washed 3 times with phosphate buffered saline (PBS) before resuspension in buffer A (50 mM Tris-HCl, pH 7.8, 5 mM MgCl2, 1 mM EGTA) and disruption with a tissue homogenizer (30 seconds, setting 4, Pt 20, Kinematica, Kriens-Lucern, Switzerland). A total membrane fraction was obtained by centrifugation at 49,000xc3x97g at 4xc2x0 C. This procedure was repeated twice and the pellet was resuspended in buffer A. Aliquots were stored at xe2x88x9270xc2x0 C. and protein concentrations were determined using the BCA(trademark) Protein Assay Reagent (Pierce, Rockford, Ill.) following the manufacturer""s recommendations.
Binding Assays
[3H]-OFQ competition studies were carried out with 77 xcexcg membrane protein in a final assay volume of 0.5 ml buffer A plus 0.1% BSA and 0.01% bacitracin (Boehringer-Mannheim, Mannheim, Germany) for one hour at room temperature. 50 nM unlabeled OFQ was used to define the non-specific binding. The assays were terminated by filtration through Whatman GF/C filters (Unifilter-96, Canberra Packard S.A., Zurich, Switzerland) pretreated with 0.3% polyethylenimine (Sigma, St. Louis, Mo., USA) and 0.1% BSA (Sigma) for 1 hour. The filters were washed 6 times with 1 ml of ice bold 50 mM Tris-HCl pH 7.5. The retained radioactivity was counted on a Packard Top-Count microplate scintillation counter after addition of 40 xcexcl of Microscint 40 (Canberra Packard). The effects of compounds were determined using at least 6 concentrations in triplicate, and determined twice. IC50 values were determined by curve fitting and these calues were converted to Ki values by the method of Cheng and Prusoff, Biochem. Pharmacol., 22, 3099, 1973.
The affinity to the OFQ-receptor, given as pKi, is in the range of 7.1 to 9.8. For example, the pKi-values of 8-(cis-4-Isopropyl-cyclohexyl)-1-phenyl-1,8-diaza-spiro[4.5]decan-4-one (Ex1.6) and (RS)-8-Acenaphthalen-1-yl-1-phenyl-1,8-diaza-spiro[4.5]decane (Ex1.19) are 9.4 and 8.6, respectively.
GTPxcex3S Binding Assay
This assay was used to define whether the compounds of this invention are agonists or antagonists of the OFQ receptor.
Agonist-mediated binding of GTPxcex3S was investigated in 96-well plates using a Scintillation Proximity Assay (SPA) using either hOFQR membranes or membranes prepared from cells transfected with the various human opiate receptors (xcexc, xcex4 and xcexa). Binding was performed in 200 xcexcl 20 mM HEPES-buffer (pH 7.4, plus 6 mM MgCl2 and 100 mM NaCl), supplemented with 20 xcexcM GDP, 10 xcexcm cold GTPxcex3S and 0.3 nM GTP[xcex335]S (1130 Ci/mmol). Twenty xcexcg membranes, 1 mg wheatgerm agglutinin SPA beads (Amersham, Little Chalfont, UK) and either OFQ (10xe2x88x925 to 10xe2x88x9210 M) or synthetic compounds (10xe2x88x924 M to 10xe2x88x929 M) were added.
The reaction mixture was incubated on a shaker for 60 min at 22xc2x0 C. and then centrifuged for 5 min at 1500 rpm in an Eppendorf 5403 centrifuge. Finally the plates were read in a Top counter (Packard).
Compounds of this invention have been shown to be agonists of the OFQ receptor having PEC50 ranges from about 5.6 to about 7.2.
The preparation of the following compounds is described in Examples 1-53:
The compounds of formula I as well as their pharmaceutically usable acid addition salts can be used as medicaments, e.g. in the form of pharmaceutical preparations. The pharmaceutical preparations can be administered orally, e.g. in the form of tablets, coated tablets, dragxc3xa9es, hard and soft gelatine capsules, solutions, emulsions or suspensions. The administration can, however, also be effected rectally, e.g. in the form of suppositories, or parenterally, e.g. in the form of injection solutions.
The compounds of formula I and their pharmaceutically usable acid addition salts can be processed with pharmaceutically inert, inorganic or organic excipients for the production of tablets, coated tablets, dragees and hard gelatine capsules. Lactose, corn starch or derivatives thereof, talc, stearic acid or its salts etc can be used as such excipients e.g. for tablets, dragxc3xa9es and hard gelatine capsules.
Suitable excipients for soft gelatine capsules are e.g. vegetable oils, waxes, fats, semi-solid and liquid polyols etc.
Suitable excipients for the manufacture of solutions and syrups are e.g. water, polyols, saccharose, invert sugar, glucose etc.
Suitable excipients for injection solutions are e.g. water, alcohols, polyols, glycerol, vegetable oils etc. Suitable excipients for suppositories are e.g. natural or hardened oils, waxes, fats, semi-liquid or liquid polyols etc.
Moreover, the pharmaceutical preparations can contain preservatives, solubilizers, stabilizers, wetting agents, emulsifiers, sweeteners, colorants, flavorants, salts for varying the osmotic pressure, buffers, masking agents or antioxidants. They can also contain still other therapeutically valuable substances.
The dosage can vary within wide limits and will, of course, be fitted to the individual requirements in each particular case. In general, the effective dosage for oral or parenteral administration is 0.01-20 mg/kg/day, preferred as a dosage of 0.1-10 mg/kg/day for all described indications. The dayly dosage for an adult of 70 kg weight is therefore between 0.7-1400 mg/day, preferred is 7-700 mg/day, although the above upper limit can also be exceeded when necessary.
The following Examples illustrate the present invention without limiting it. All temperatures are given in degrees Celsius.